The bow and arrow represents one of the great technological advancements in weaponry in the ancient world. In fact, the bow is the first mechanical device that could store energy, as the arrow was held in the string before its release. Recent distance records in flight archery for pulled bows are around one third mile, the longest crossbow shot is 1.16 miles! Bows and arrows were used just about everywhere in the world except Australia where spear throwers were the preferred weapon. Triangular shaped arrow points were one of the most common types of arrow points used on the tips of arrows.
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The bow and arrow represents one of the great technological advancements in weaponry in the ancient world. In fact, the bow is the first mechanical device that could store energy, as the arrow was held in the string before its release. Recent distance records in flight archery for pulled bows are around one third mile, the longest crossbow shot is 1.16 miles! Bows and arrows were used just about everywhere in the world except Australia where spear throwers were the preferred weapon. Triangular shaped arrow points were one of the most common types of arrow points used on the tips of arrows.
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The Willow Tree series was replaced because of a new technology. Rather than simply using the older hammer striking method Richard Doty has suggested Hull changed to a rocker arm press. The dies needed for a rocker arm press were quite different from dies used in the hammer strike method. A rocker press used large-sized rectangular shaped dies with a curved face so that the die could rock back and forth. The image for the coin was then engraved on the curved face of the rocker, one rocker for the obverse and another for the reverse (click here for picture of rocker dies). The two rocker dies would then be mounted face to face in the press. By pulling a lever the upper and lower rockers would press against each other with a rolling motion (click here for picture of a rocker press). As long as the two dies were properly aligned a blank planchet placed between them would be impressed with the design of the dies.
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The Willow Tree series was replaced because of a new technology. Rather than simply using the older hammer striking method Richard Doty has suggested Hull changed to a rocker arm press. The dies needed for a rocker arm press were quite different from dies used in the hammer strike method. A rocker press used large-sized rectangular shaped dies with a curved face so that the die could rock back and forth. The image for the coin was then engraved on the curved face of the rocker, one rocker for the obverse and another for the reverse (click here for picture of rocker dies). The two rocker dies would then be mounted face to face in the press. By pulling a lever the upper and lower rockers would press against each other with a rolling motion (click here for picture of a rocker press). As long as the two dies were properly aligned a blank planchet placed between them would be impressed with the design of the dies.
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Ixodes scapularis is commonly known as the deer tick or blacklegged tick, and in some parts of the USA as the bear tick. It is a hard-bodied tick of the eastern and northern Midwestern United States.
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The beetle species Popillia japonica is commonly known as the Japanese beetle. It is about 15 millimetres (0.6 in) long and 10 millimetres (0.4 in) wide, with iridescent copper-colored elytra and green thorax and head. It is not very destructive in Japan, where it is controlled by natural predators, but in North America it is a serious pest of about 200 species of plants, including rose bushes, grapes,hops, canna, crape myrtles, birch trees, linden trees and others.
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Stinkbugs –Pentatomidae, Greek pente meaning five and tomos meaning section, are a family of insects belonging to order Hemiptera including some of the stink bugs and shield bugs.The scutellum body is typically half of an inch long, green or brown color, usually trapezoidal in shape, giving this family the name “shield bug”. The tarsi are 3-segmented. The forewings of stink bugs are called hemelytra, with the basal half thickened while the apex is membranous (as are the hindwings). The stink bug derives its name from its tendency to eject a foul smelling glandular substance secreted from pores in the thorax when disturbed.
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Cicadas are in the superfamily Cicadoidea. Their eyes are prominent, though not especially large, and set wide apart on the anterior lateral corners of the frons. Cicadas live in temperate-to-tropical climates where they are among the most-widely recognized of all insects, mainly due to their large size and unique sound.
Cicadas live underground as nymphs for most of their lives, at depths ranging from about 30 centimetres (0.98 ft) down to 2.5 metres (8.2 ft). The nymphs feed on xylem sap from roots and have strong front legs for digging.
In the final nymphal instar, they construct an exit tunnel to the surface and emerge. They then moult (shed their skins) on a nearby plant for the last time and emerge as adults. The exuvia, or abandoned exoskeleton, remains, still clinging to the bark of trees.
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Treehoppers are members of the familyMembracidae, a group of insects related to the cicadas and the leafhoppers. About 3,200 species of treehoppers in over 400 genera are known.
The eggs may be parasitised by wasps, such as the tiny fairyflies (Mymaridae) and Trichogrammatidae. The females of some membracid species sit over their eggs to protect them from predators and parasites, and may buzz their wings at intruders. The females of some gregarious species work together to protect each other’s eggs. In at least one species, Publilia modesta, mothers serve to attract ants when nymphs are too small to produce much honeydew. Some other species make feeding slits for the nymphs.
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Stinkbugs –Pentatomidae, Greek pente meaning five and tomos meaning section, are a family of insects belonging to order Hemiptera including some of the stink bugs and shield bugs.The scutellum body is typically half of an inch long, green or brown color, usually trapezoidal in shape, giving this family the name “shield bug”. The tarsi are 3-segmented. The forewings of stink bugs are called hemelytra, with the basal half thickened while the apex is membranous (as are the hindwings). The stink bug derives its name from its tendency to eject a foul smelling glandular substance secreted from pores in the thorax when disturbed.
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Stinkbugs –Pentatomidae, Greek pente meaning five and tomos meaning section, are a family of insects belonging to order Hemiptera including some of the stink bugs and shield bugs.The scutellum body is typically half of an inch long, green or brown color, usually trapezoidal in shape, giving this family the name “shield bug”. The tarsi are 3-segmented. The forewings of stink bugs are called hemelytra, with the basal half thickened while the apex is membranous (as are the hindwings). The stink bug derives its name from its tendency to eject a foul smelling glandular substance secreted from pores in the thorax when disturbed.
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The Candy-Striped Treehopper (Graphocephala coccinea) is a meadow and woodland-dwelling species of brightly colored leafhopper native to North and Central America, from Canada south to Panama.
G. coccinea adults measure 6.7–8.4 mm in length and have vivid blue (or green) and red (or orange-red) stripes on their wings and the top of their thorax combined with bright yellow coloration on their head, legs, abdomen, and elsewhere.
Leafhoppers feed on plant sap with the aid of specialized mouthparts.
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Bedbugs are parasitic insects of the cimicid family that feed exclusively on blood. Cimex lectularius, the common bed bug, is the best known, as it prefers to feed on human blood. Other Cimex species specialize in other animals, e.g., bat bugs, such as Cimex pipistrelli (Europe), Cimex pilosellus (western US), and Cimex adjunctus (entire eastern US).
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Red blood cells (RBCs), also called erythrocytes, are the most common type of blood cell and the vertebrate organism’s principal means of delivering oxygen (O2) to the body tissues—via blood flow through the circulatory system] RBCs take up oxygen in the lungs or gills and release it into tissues while squeezing through the body’s capillaries. They are between 6-8 microns in diameter.
The cytoplasm of erythrocytes is rich in hemoglobin, an iron-containing biomolecule that can bind oxygen and is responsible for the red color of the cells. The cell membrane is composed of proteins and lipids, and this structure provides properties essential for physiological cell function such as deformability and stability while traversing the circulatory system and specifically the capillary network.
In humans, mature red blood cells are flexible and oval biconcave disks. They lack a cell nucleus and most organelles, in order to accommodate maximum space for hemoglobin. Approximately 2.4 million new erythrocytes are produced per second in human adults. The cells develop in the bone marrow and circulate for about 100–120 days in the body before their components are recycled by macrophages. Each circulation takes about 20 seconds. Approximately a quarter of the cells in the human body are red blood cells.
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Eyes are the organs of vision. They detect light and convert it into electro-chemical impulses in neurons. In higher organisms, the eye is a complex optical system which collects light from the surrounding environment, regulates its intensity through a diaphragm, focuses it through an adjustable assembly of lenses to form an image, converts this image into a set of electrical signals, and transmits these signals to the brain through complex neural pathways that connect the eye via the optic nerve to the visual cortex and other areas of the brain. Eyes with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system. Image-resolving eyes are present in molluscs, chordates and arthropods.
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Compound eyes are found among the arthropods and are composed of many simple facets which, depending on the details of anatomy, may give either a single pixelated image or multiple images, per eye. Each sensor has its own lens and photosensitive cell(s). Some eyes have up to 28,000 such sensors, which are arranged hexagonally, and which can give a full 360° field of vision. Compound eyes are very sensitive to motion. Some arthropods, including many Strepsiptera, have compound eyes of only a few facets, each with a retina capable of creating an image, creating vision. With each eye viewing a different thing, a fused image from all the eyes is produced in the brain, providing very different, high-resolution images.
